RESUMO
Babaco (Vasconcellea × heilbornii) is a subtropical species in the Caricaceae family. The plant is native to Ecuador and represents an important crop for hundreds of families. The objective of this study was to characterize, at the genomic level, two new babaco viruses identified by high-throughput sequencing. The viruses, an ilarvirus and a nucleorhabdovirus, were found in a symptomatic babaco plant from a commercial nursery in the Azuay province of Ecuador. The tripartite genome of the new ilarvirus, provisionally named babaco ilarvirus 1 (BabIV-1), is related to subgroup 3 ilarviruses, including apple mosaic virus, apple necrotic mosaic virus, and prunus necrotic ringspot virus as the closest relatives. The genome of the nucleorhabdovirus, provisionally named babaco nucleorhabdovirus 1 (BabRV-1), showed the closest relation with joa yellow blotch-associated virus and potato yellow dwarf nucleorhabdovirus. Molecular-based detection methods found BabIV-1 and BabRV-1 in 21% and 36%, respectively, of plants surveyed in a commercial babaco nursery, highlighting the importance of enforcing virus testing and nursery certification programs for babaco.
Assuntos
Bromoviridae , Caricaceae , Ilarvirus , Rhabdoviridae , Humanos , Viroma , Ilarvirus/genética , PlantasRESUMO
Potato yellowing virus (PYV, original code SB-22), an unassigned member of the Genus Ilarvirus Family Bromoviridae, has been reported infecting potatoes in Peru, Ecuador and Chile. It is associated with symptomless infections, however yellowing of young leaves has been observed in some potato cultivars. Thirteen potato and yacon isolates were selected after routine screening of CIP-germplasm and twenty-four were identified from 994 potato plants collected in Peru whereas one was intercepted from yacon in the UK. These isolates were identified using high throughput sequencing, ELISA, host range and RT-PCR. Here we report the sequence characterization of the complete genomes of nine PYV isolates found infecting Solanum tuberosum, four complete genome isolates infecting Smallanthus sonchifolius (yacon), and in addition 15 complete RNA3 sequences from potato and partial sequences of RNA1, 2 and 3 of isolates infecting potato and yacon from Ecuador, Peru and Bolivia. Results of phylogenetic and recombination analysis showed RNA3 to be the most variable among the virus isolates and suggest potato infecting isolates have resulted through acquisition of a movement protein variant through recombination with an unknown but related ilarvirus, whereas one yacon isolate from Bolivia also had resulted from a recombination event with another related viruses in the same region. Yacon isolates could be distinguished from potato isolates by their inability to infect Physalis floridana, and potato isolates from Ecuador and Peru could be distinguished by their symptomatology in this host as well as phylogenetically. The non-recombinant yacon isolates were closely related to a recently described isolate from Solanum muricatum (pepino dulce), and all isolates were related to Fragaria chiloensis latent virus (FCiLV) reported in strawberry from Chile, and probably should be considered the same species. Although PYV is not serologically related to Alfalfa mosaic virus (AMV), they are both transmitted by aphids and share several other characteristics that support the previous suggestion to reclassify AMV as a member in the genus Ilarvirus.
Assuntos
Afídeos/virologia , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Especificidade de Hospedeiro , Ilarvirus/genética , Doenças das Plantas/virologia , Animais , Ilarvirus/classificação , Ilarvirus/isolamento & purificação , Filogenia , Folhas de Planta/virologia , Recombinação Genética , Solanum tuberosum/virologia , América do Sul , Reino UnidoRESUMO
There is no molecular characterization of Brazilian isolates of Prunus necrotic ringspot virus (PNRSV), except for those infecting peach. In this research, the causal agent of rose mosaic was determined and the movement (MP) and coat (CP) protein genes of a PNRSV isolate from rose were molecularly characterized for the first time in Brazil. The nucleotide and deduced amino acid sequences of MP and CP complete genes were aligned and compared with other isolates. Molecular analysis of the MP and CP nucleotide sequences of a Brazilian PNRSV isolate from rose and others from this same host showed highest identities of 96.7% and 98.6%, respectively, and Rose-Br isolate was classified in PV32 group.
Inexiste caracterização molecular de isolados brasileiros de Prunus necrotic ringspot virus (PNRSV), exceto aqueles de pessegueiros. Neste trabalho, o agente causal do mosaico da roseira foi determinado e os genes das proteínas de movimento (MP) e capsidial (CP) de um isolado de PNRSV de roseira foram molecularmente caracterizados pela primeira vez no Brasil. As sequências completas de nucleotídeos e de aminoácidos deduzidos da MP e da CP foram alinhadas e comparadas com outros isolados. Análises das sequências de nucleotídeos da MP e da CP do isolado brasileiro de PNRSV de roseira e outros isolados da mesma hospedeira revelaram altas identidades de 96,7% e 98,6%, respectivamente, sendo o isolado Rose-Br classificado no grupo PV32.
Assuntos
Doenças das Plantas , Prunus , Rosa , Vírus do Mosaico/isolamento & purificação , Vírus do Mosaico/patogenicidadeRESUMO
There is no molecular characterization of Brazilian isolates of Prunus necrotic ringspot virus (PNRSV), except for those infecting peach. In this research, the causal agent of rose mosaic was determined and the movement (MP) and coat (CP) protein genes of a PNRSV isolate from rose were molecularly characterized for the first time in Brazil. The nucleotide and deduced amino acid sequences of MP and CP complete genes were aligned and compared with other isolates. Molecular analysis of the MP and CP nucleotide sequences of a Brazilian PNRSV isolate from rose and others from this same host showed highest identities of 96.7% and 98.6%, respectively, and Rose-Br isolate was classified in PV32 group.(AU)
Inexiste caracterização molecular de isolados brasileiros de Prunus necrotic ringspot virus (PNRSV), exceto aqueles de pessegueiros. Neste trabalho, o agente causal do mosaico da roseira foi determinado e os genes das proteínas de movimento (MP) e capsidial (CP) de um isolado de PNRSV de roseira foram molecularmente caracterizados pela primeira vez no Brasil. As sequências completas de nucleotídeos e de aminoácidos deduzidos da MP e da CP foram alinhadas e comparadas com outros isolados. Análises das sequências de nucleotídeos da MP e da CP do isolado brasileiro de PNRSV de roseira e outros isolados da mesma hospedeira revelaram altas identidades de 96,7% e 98,6%, respectivamente, sendo o isolado Rose-Br classificado no grupo PV32.(AU)